Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloblastic leukemia with specific clinical, morphologic and genetic features and a good response to all trans retinoic acid (ATRA). However, extramedullary (EM) relapse is an interesting feature of these cases, especially those treated with ATRA. Recently, we have encountered an EM relapse in the pleura in a case with APL receiving an ATRA containing regimen. This case is reported and the relevant literature is reviewed.